variants/Bicolour/class.js

   1 import ChessRules from "/base_rules.js";
   2 import {Random} from "/utils/alea.js";
   3 import {ArrayFun} from "/utils/array.js";
   4
   5 export default class BicolourRules extends ChessRules {
   6
   7   static get Options() {
   8     return {
   9       select: C.Options.select,
  10       input: [
  11         {
  12           label: "King takes all",
  13           variable: "takeboth",
  14           type: "checkbox",
  15           defaut: true
  16         },
  17         {
  18           label: "Capture king",
  19           variable: "taking",
  20           type: "checkbox",
  21           defaut: false
  22         }
  23       ],
  24       styles: ["balance", "capture", "cylinder", "dark",
  25                "doublemove", "madrasi", "progressive", "zen"]
  26     };
  27   }
  28
  29   get hasFlags() {
  30     return false;
  31   }
  32
  33   canTake([x1, y1], [x2, y2]) {
  34     return (
  35       this.getPiece(x2, y2) == 'k' ||
  36       (this.getPiece(x1, y1) == 'k' && this.options["takeboth"]) ||
  37       super.canTake([x1, y1], [x2, y2])
  38     );
  39   }
  40
  41   genRandInitBaseFen() {
  42     if (this.options["randomness"] == 0)
  43       return { fen: "rqbnkbnr/pppppppp/8/8/8/8/PPPPPPPP/RQBNKBNR", o: {} };
  44
  45     // Place pieces at random but the king cannot be next to a rook or queen.
  46     // => One bishop and one knight should surround the king.
  47     let pieces = {w: new Array(8), b: new Array(8)};
  48     let flags = "";
  49     for (let c of ["w", "b"]) {
  50       if (c == 'b' && this.options["randomness"] == 1) {
  51         pieces['b'] = pieces['w'];
  52         break;
  53       }
  54       let positions = ArrayFun.range(8);
  55       const kingPos = randInt(8);
  56       let toRemove = [kingPos];
  57       let knight1Pos = undefined;
  58       let bishop1Pos = undefined;
  59       if (kingPos == 0) {
  60         if (Random.randBool())
  61           knight1Pos = 1;
  62         else
  63           bishop1Pos = 1;
  64         toRemove.push(1);
  65       }
  66       else if (kingPos == V.size.y - 1) {
  67         if (Random.randBool())
  68           knight1Pos = V.size.y - 2;
  69         else
  70           bishop1Pos = V.size.y - 2;
  71         toRemove.push(V.size.y - 2);
  72       }
  73       else {
  74         knight1Pos = kingPos + (Random.randBool() ? 1 : -1);
  75         bishop1Pos = kingPos + (knight1Pos < kingPos ? 1 : -1);
  76         toRemove.push(knight1Pos, bishop1Pos);
  77       }
  78       const firstPieces = [kingPos, knight1Pos, bishop1Pos]
  79         .filter(elt => elt !== undefined);
  80       firstPieces
  81         .sort((a, b) => b - a)
  82         .forEach(elt => positions.splice(elt, 1));
  83       let randIndex = undefined;
  84       if (bishop1Pos === undefined) {
  85         const posWithIdx = positions.map((e,i) => { return {e: e, i: i}; });
  86         let availableSquares = posWithIdx.filter(p => p.e % 2 == 0);
  87         randIndex = randInt(availableSquares.length);
  88         bishop1Pos = availableSquares[randIndex].e;
  89         positions.splice(availableSquares[randIndex].i, 1);
  90       }
  91       const posWithIdx = positions.map((e,i) => { return {e: e, i: i}; });
  92       const rem1B = bishop1Pos % 2;
  93       let availableSquares = posWithIdx.filter(p => p.e % 2 == 1 - rem1B);
  94       randIndex = randInt(availableSquares.length);
  95       const bishop2Pos = availableSquares[randIndex].e;
  96       positions.splice(availableSquares[randIndex].i, 1);
  97       if (knight1Pos === undefined) {
  98         randIndex = randInt(5);
  99         knight1Pos = positions[randIndex];
 100         positions.splice(randIndex, 1);
 101       }
 102       randIndex = randInt(4);
 103       const knight2Pos = positions[randIndex];
 104       positions.splice(randIndex, 1);
 105       randIndex = randInt(3);
 106       const queenPos = positions[randIndex];
 107       positions.splice(randIndex, 1);
 108       const rook1Pos = positions[0];
 109       const rook2Pos = positions[1];
 110       pieces[c][rook1Pos] = "r";
 111       pieces[c][knight1Pos] = "n";
 112       pieces[c][bishop1Pos] = "b";
 113       pieces[c][queenPos] = "q";
 114       pieces[c][kingPos] = "k";
 115       pieces[c][bishop2Pos] = "b";
 116       pieces[c][knight2Pos] = "n";
 117       pieces[c][rook2Pos] = "r";
 118     }
 119
 120     return {
 121       fen: (
 122         pieces["b"].join("") +
 123         "/pppppppp/8/8/8/8/PPPPPPPP/" +
 124         pieces["w"].join("").toUpperCase()
 125       ),
 126       o: {}
 127     };
 128   }
 129
 130   underCheck(square_s) {
 131     return super.underCheck(square_s, ['w', 'b']);
 132   }
 133
 134 };